So I experienced this problem last year and thankfully it went away... until now. I generally keep my temp somewhere between 68 and 74. But for the past few days it seems the passenger side blows colder than the drivers. This is most noticeable at 80 and above, the only way I can get the passenger side to get warm is to take it to "Hi" and then bring it back down a little but once I bring it back down to a colder temp it never gets warm again unless I take it to high. In the ams on my way to work I usually have it around 78/79 and I happened to notice awhile back that the passenger side was freezing. I have never thought the TL had a very good ac system, its never gotten cold enough to my liking but I have been assured by 2 dealers its fine, right now the passenger side gets colder than a polar bears ass the way I wish the drivers would. I did the self diagnostic and the passenger side lit up/flashed the top bar on the 8 an the bottom right which indicates a problem with the passenger side air mix motor. I took the car to my mechanic today and he diagnosed that the ac expansion valve is getting stuck... from the research I have done, the expansion valve doesn't cause this. And just to clarify I have ran the self diagnostic several times, it doesn't indicate a problem everytime even if I'm experiencing the issue and this problem occurs whether or not I have the ac on or off. Mechanic hasn't gave my a price yet but... I have a feeling the passenger side air mix motor is cheaper. Any info someone can provide is greatly appreciated. Oh and BTW when this happened last year it happened one time when it was raining andI had to use defrost, passenger side cleared up fine but drivers stayed foggy. Figured I'd spill every detail

 

Sounds like you may have some blockage in the drivers side vents.

 

It's definitely not an expansion valve because theres only one and it works on the whole system so it cant cause one side to be any different than the other. The side mix door seems like its not operating correctly, weather its the actuator or something else binding will still need to be determined.

 

One thing I forgot to mention. When it first started doing it last year, if I ran the self diagnostic thing it would usually fix itself. My mechenic did a full ac service today "whatever that consists of" but didn't charge me. This go round it isn't stopping no matter what

 

By no means am I close to being a mechanic I am mechanically challenged lol, just a pro at googling, and what you said is exactly what I was thinking. I'm gonna mention it to him again tomorrow and see what he says if I don't like what I hear I may take it somewhere else

 

I have the same issue with my 06 TL. In my case it's the drivers side that's ice cold and the passenger side that is warm/normal. It's odd because it only behaves this way when it's warmer out. What I have noticed is when the temp is below 50 F it's fine, when it's above 50 and I set the temp to say 75 F I get ice cold AC on the drivers side and normal temp's on the passenger side. Of course I do the same thing to fix it, crank the head up to full, then it starts blowing hot air, it's a pain in the butt. I think a temp sensor has failed on the drivers side. Did you end up fixing this? I am thinking of taking my car to Acura Dealer as it's still covered under the extended warranty from Honda.

 

was there ever a fix to this .. i noticed that my passenger side blows out warm when the a/c is on low

 

Driver's side blows warmer air than passenger side on mine. Did a search hoping there was a fix but apparently not.

My son was wondering why I was complaining about the a/c, now I know why. His side was nice and cold.

Problem is worse if I get right on the freeway, once I get off the freeway or slow down, driver's side air gets noticeably colder. Sometimes it does that (cools off) when I accelerate hard around slower traffic. Also, the warmer is outside, the more noticeable the problem is. And air blows through just as hard on both sides.

The engine speed variable leads me to believe that maybe the system is vacuum controlled?

 

So, if this is the problem, why not fix it? a sticking driver side door-mix linkage is a known problem with the RDX, which just requires re-lubrication of the linkage - there is a TSB for this problem on the RDX - and similar linkage is used on passenger side of the RDX. I am puzzled by the length of this thread, without anyone actually trying to just fix, or have fixed, the door linkage?

Anyone can run the self-diagnostic, no additional computer or equipment is required - just the car can diagnose itself, as indicated in the first post.

 

We just like to talk here in the 3G TL section.

 

I've had this same exact problem for the past three years. The drivers side works normally. The passenger side blows too cold.

Usually happens on a chilly but humid rainy day when I want the heat up a bit. Only fix is to set the passenger side temp to Hi for a few minutes and then it'll follow proper temp as selected. Tried takin it to a dealership and was told all was normal.

 

Similar issues on my '05. Usually all is well, but from time to time the drivers side is not nearly as cold as the passenger side. My wife brings a blanket and a hoodie sweatshirt when we go on road trips because she freezes while I am nearly sweating while driving. My car was at the dealer several times for this and never once could they find any real issue. The first time they claimed the system was low on freon and charged it. I finally gave up and just deal with it now. It doesn't get nearly as bad as long as I don't use the dual-zone controls. When it gets bad, I take the controls down to "Lo" and just manually control the fan speed. It seems to balance the temps out more.

In the winter, I do not think I have any issues. Although I am rarely the passenger in the winter so I really don't know.

 

For those having problems, particularly different temps from driver to passenger sides, has anyone actually verified the actual temp difference, by using two different temp gauges? stuck in the side vents by the doors?

The RDX FSM (factory service manual) states that the temp difference between the driver's and passenger's side vents may vary by up to 20 degrees, as NORMAL.

If the difference is more than 20 degrees that would indicate either:

1) one of the air mix doors is inoperable (driver or passenger side)

2) OR, there is a low freon charge - discharge (HIGH) and suction (LOW) pressures are low.

When testing or checking the A/C output temp, it is best to perform the FSM standard test. If you don't have the TL FSM, probably the RDX FSM test is close enough, as described here:

https://acurazine.com/forums/showthread.php?p=13955220#post13955220